The invention relates to a retractor for use in endoscopic surgery, comprising a shaft (1) having a hand piece (2) arranged on the proximal end thereof and whose distal end can be moved out of an initially extended and straight position, whereby the adjustable distal end consists of several link elements (4) that can be moved into a ring-shaped structure and said ring-shaped structure can be bent in relation to the shaft (1). The invention also relates to a medical instrument for introducing a retractor into a human or animal body and to a method for the use of a retractor in endoscopic surgery.
Retractors are used in endoscopic surgery to remove organs and similar bodily parts, which are not to be treated, from the operating area during an operation using endoscopic viewing. Contrary to the fan-type retractors customarily used, retractors of the type mentioned at the outset have the advantage that, upon re-closing the retractor, scarcely any further danger exists that the bodily parts handled by the retractor will suffer bruising injuries. Such a fan-type retractor is known, for example, from U.S. Pat. No. 5,307,805.
A retractor of the aforementioned type is known for instance from DE 693 10 345 T2. These retractors, in straight, extended position, are introduced into the body, for instance the abdominal area, and once inserted, are displaced by turning the hand piece. Use of the adjustable link elements can lead to bruising of bodily parts to be treated. In addition, the known types of retractors can only be partially cleansed, particularly in the area connecting the shaft and the hand piece.
On the basis of this technological status, the invention is based on the task of creating a retractor that ensures safe, atraumatic use and which in addition can be handled in a highly hygienic manner. In addition, the invention is based on the task of providing a medical instrument for introducing a retractor into human or animal bodies as well as a method for using a retractor in endoscopic surgery.
The invention solves this task in that the distal end of the shaft can be moved into a closed ring structure and that the closed ring structure can be bent continuously to an angle up to 90 degrees to the shaft.
Because, in the retractor of this invention, the retractor can be moved into a closed ring structure, it becomes possible to avoid bruising injuries of the kind that can occur in practice with known retractors. The design of the closed ring structure, in addition, has the advantage that the moved distal end of the shaft is stable and weight bearing in itself. The possibility of also bending the ring structure in relation to the shaft allows for an especially simple and safe use of the retractor of this invention.
In accordance with a first demonstration of the invention, the distal end of the shaft is moved by means of a tool while being viewed in the endoscope. This demonstration of the invention is distinguished by its simple structure, since it dispenses with an independent mechanism for moving the distal end of the retractor shaft.
To facilitate opening and/or closing of the ring structure by means of a tool, recesses are provided in the front most link element, and a tool, such as a pincer in particular, can engage in said recesses in order to move the link element.
In a second execution of the invention, the distal end of the retractor shaft can be moved by means of an interior or exterior Bowden cable.
In accordance with an initial practical demonstration, the locking element is designed as a notch element which can be secured in a notch retainer of the first link element that is connected with the immobile part of the shaft. This firm interlocking makes it possible to apply relatively great pressure through the closed ring structure.
In an alternative version of the invention, the locking element consists of a magnet.
In accordance with a practical demonstration of the invention, the ring structure can be bent at least 90 degrees to the shaft by means of a hinge between the rigid shaft portion and the first link element in both directions from the level of the ring structure.
To facilitate sterilizing the retractor of this invention, it is further proposed that the hand piece and shaft are reversibly connected by means of an adapter piece so that the parts can be individually cleaned.
The shaft and the adapter piece connected to the hand piece may be assembled in an especially simple manner because the adapter piece and shift are joined together by engaged notching.
To secure the shaft to the adapter piece it is proposed that the adapter piece have an axial bore in which a notch element is mounted which can be activated from outside by means of a button for securing the shaft. In order to connect the shaft and hand piece, it is merely necessary to move the proximal free end of the shaft into the axial bore of the adapter piece connected with the hand piece, until the notch element in the adapter piece secures the shaft by notching.
To ensure a firm connection between shaft and adapter piece by means of a notch element of the adapter piece, and also to allow the release of this connection through activation of the button situated on the outside of the adapter piece, the notch element is spring-loaded in the notch position.
Handling the retractor of this invention by the operating team can be facilitated if the weight of the hand piece is determined in such a way that the hand piece serves as a counterweight to the bodily part gripped by the ring structure.
The invention""s solution to the task of providing a medical instrument for introducing a retractor into a human or animal body is characterized by a shaft with a basically semicircular profile in cross-section, whose distal end has the shape of a self-cutting tip.
The use of this insertion device, according to the invention, offers an alternative to the use of classical hollow-cylinder trocars. The invention""s insertion device, after the retractor is introduced into the body, can be removed again so that the retractor can then be freely moved.
The invention""s method for using a retractor in endoscopic surgery is characterized by the following steps:
a) introducing a retractor shaft in straight, extended position into the body through an artificial bodily opening;
b) moving the distal end of the shaft into a closed ring structure;
c) bending the displaced distal end of the shaft from the level of the ring structure opposite the shaft
d) removal of an internal organ or other tissue from the operating area in order to make room and visibility for the endoscopic intervention; and
e) replacing the retractor shaft into the straight, extended position for removal from the body
For the introduction of the invention""s retractor into the body it is suggested that a medical instrument be used whose shaft has a basically semicircular cross-section and whose distal end has the form of a self-cutting tip. Use of this insertion tool designed according to the invention allows a simple, safe introduction of the retractor and also ensures that this tool can be removed again after the retractor is inserted in order to increase the working space available to the retractor.